1. Technical Field
The present invention relates in general to systems and methods for using brooms and blowers to remove debris from various surfaces. More particularly, the present invention relates to an apparatus and method for controlling an integrated broom and blower system which can be applied to road surfaces, such as an airport runway, to remove snow and other debris which may accumulate thereon.
2. History of Related Art
Truck-mounted systems for removing snow and debris from various road surfaces, such as airport runways, typically include a front-mounted broom and a rear-mounted air blast system, or blower system. Turning now to prior art FIG. 1, it can be seen that as the truck 20 moves over the road surface 10, the rotating broom 40 on the front of the truck 20 contacts the snow or debris 15 on the road surface 10 and brushes the snow or debris 15 to the front and to one side of truck 20. The air blast system or blower system 30 on the truck 20 then blows the snow or debris 15 which has been swept to one side away from the truck 20 and across the road surface 10.
As can be more easily seen in prior art FIG. 2, when it is desired to push the snow or debris 15 to one side of a runway 12, for example the left side 13, the truck 20 moves along the right side 14 of the runway 12 until it reaches the end 70. Upon reaching the end 70 of the runway 12, the operator must re-configure the sweeping and blowing apparatus on the truck 20 by repositioning the broom 40 and redirecting the air blast 50 from the left side of the blower system 30 (as the truck moves toward the end 70 of the runway 12) to the right side of the blower system 30 (as the truck moves away from the end 70 of the runway 12). Note that in the truck 20 moving up the path 60 along the right side 14 of the runway 12, the broom 40 is positioned so that the near end 42 is closest to the left or driver side of the truck 20, at a positive angle "PHgr". When the truck 20 turns around 80 at the upper end 70 of the runway 12, the angular orientation "PHgr" of the broom 40 with respect to the truck 20 must be changed, and the direction of the air blast 50 from the blower switched from the left side to the right side (i.e., to the direction of air blast 90). This is accomplished by picking up the broom 40 so that the broom bristles are out of contact with the ground and then causing the entire broom head to change its angular orientation with respect to the truck 20, so that the broom 40xe2x80x2 is properly re-oriented. Typically the angular orientation "PHgr" is preset to about xc2x135xc2x0, however in special situations, a smaller angle may be used. For the purposes of this document, it will be assumed that a positive angle "PHgr" refers to a xe2x80x9cleftxe2x80x9d broom 40 direction (i.e. the near end 42 of the broom is closest to the driver/left side of the truck, as viewed from a person seated inside the driver""s compartment of the truck), and that a negative angle "PHgr" refers to a xe2x80x9crightxe2x80x9d broom 40xe2x80x2 direction (i.e., the far end 41 of the broom is closer to the passenger/right side of the truck, as viewed by someone seated inside the driver""s compartment of the truck). Similarly, it will be assumed that xe2x80x9cblowing leftxe2x80x9d 50 means blowing toward the driver/left side of the truck, and that xe2x80x9cblowing rightxe2x80x9d 90 means blowing toward the passenger/right side of the truck.
While the truck-mounted snow brooms and air blast systems found in the prior art and described above have received wide acceptance, they are not without their problems. As described above, changing the direction of the blower system 30 and the angular orientation of the broom 40, 40xe2x80x2 keeps the snow or debris 15 moving from the right side 14 of the runway 12 to the left side 13 of the runway 12. Typically, the direction of the air blast from the blower system 30 is controlled by the use of two curved nozzles 32, 34 mounted on either side of the truck 20 (i.e., one nozzle 34 on the left side of the truck 20, and the other nozzle 32 on the right side of the truck 20). Thus, after turning the truck 20 around 80, when it is desired to push the snow or debris 15 to the right side of the truck 20, the nozzle 34 on the left side of the truck 20 is deployed, the right nozzle 32 is stowed, and the blower system 30 causes high velocity air to pass from the left side to the right side of the truck 20 to blow the snow or debris 15 in the same direction that it is pushed by the broom 40.
When the truck 20 comes to the end 70 of the runway 12, the orientation of the broom 40 and the direction of the blower system 30 are both reconfigured for another pass in the opposite direction down the runway 12 (i.e. as the truck 20 changes direction to follow path 100 after following path 60). In prior art systems, the reconfiguration of the truck 20 for the second pass 100 down the runway 12 begins by first changing the nozzles 32, 34 in the blower system 30 on the truck from one side to the other. Following the repositioning of the blower system nozzles 32, 34, the broom 40 in the front of the truck 20 is repositioned. In the prior art, the broom 40 and the nozzles 32, 34 are hydraulically controlled by operating a plurality of hydraulic sequence valves controlled by electric relays.
It is usually up to the operator to match the configuration angle of the broom 40 and the direction of operation for the blower system 30. Using a prior art operator""s console, a joy stick is typically used to change the angular orientation "PHgr" of the broom 40. If a broom position is selected other than travel to a full-stop limit, a xe2x80x9ccancelxe2x80x9d button must be pressed to terminate broom movement as the broom arrives at the selected intermediate position.
In prior art systems, the vertical position of the broom 40 (which determines the amount of contact between the broom bristles and the runway surface 12) is regulated using a mechanical stop located underneath the truck 20. When the operator wants to change the vertical position of the broom 40 with respect to the surface of the runway 12, it is necessary for the operator to crawl under the truck in the snow and debris 15 and physically adjust the position of the mechanical stop. Therefore, about every six hours or so, the bristles wear down and the operator must exit the cab of the truck 20 to reconfigure the broom 40.
Thus, what is needed is a vehicle, apparatus, and method for controlling a broom and blower system which obviates the need for the system operator to closely monitor the state of the broom and blower system, and acts in at least a semi-automatic fashion to reconfigure the broom and blower system after each pass down a road surface, such as a runway. Equally beneficial would be a vehicle, apparatus, and method for controlling a broom and blower system which provide the capability to override automatic reconfiguration under special circumstances, such as for blowing snow off of runway lights, wherein the blower direction does not necessarily correspond to that of the broom head. Such an apparatus and method would save a substantial amount of time, speeding up debris/snow clearance operations significantly. This is especially important when airplanes, potentially low on fuel, are waiting to land on the runway surface. The foregoing and other problems have been addressed by the vehicle, apparatus, and method for controlling a truck-mounted snow broom and blower system of the present invention.
The apparatus of the invention for controlling a broom and blower system typically includes several interconnected modules (which may be physically realized using software, hardware, or a combination of these) which interact to process command inputs. For example, the operator will typically be able to enter commands to turn the broom on/off (broom state), to move the broom up/down (broom height), and to orient the broom left/right (broom direction), using a push-button console. In the case of adjusting the broom height, or direction, the operator has the choice of moving the broom to a full-stop position, or to some intermediate position, determined by the amount of time the command button is held closed by the operator. Thus, broom state, broom height, and broom direction command modules are all logically connected to a command input module, which receives the operator""s commands. Similarly, blower state (blower on/off) and direction (blower left/right) modules are also logically connected to the command input module. It should be noted that some command inputs may also originate from within various parts of the system itself, such as when it is necessary to turn off the blower to stow a blower nozzle (i.e., the command to blow to the right, for example, can also serve as a command input to turn off the blower, tow the right blower nozzle, deploy the left blower nozzle, and turn on the blower).
The apparatus also includes several actuator modules which translate command inputs into appropriate physical motion and/or electrical/hydraulic/mechanical signals so as to operate various elements of the broom and blower system. Thus, the command modules are in logical communication with the blower and broom actuator modules, as well as other system element actuator modules.
The vehicle of the invention includes a broom, a blower system, and the control apparatus, described above. The control apparatus, typically mounted in the cab of the vehicle, acts to operate the rotating broom assembly and the direction blower assembly in an integrated manner, by monitoring command inputs and the state of various aspects of the broom and blower system.
The method of the invention for operating a rotating broom and a directional blower includes the steps of receiving a command input, measuring the duration of the command input, and determining whether the command input is a broom state command, a broom height command, a broom direction command a blower state command, or a blower direction command. If the command is one which requires the possible selection of an intermediate position, e.g., a broom direction command, then the command is followed as long as the operator (or other source of the command) enters the command. If the command is entered for a very short duration, for example, less than a second, then the command input is latched and held for the length of time required to reach a full-stop position. For example, momentary activation of a button on the operator""s console causing a short duration broom height command having a value of xe2x80x9cUPxe2x80x9d to be initiated will typically be latched and held for ten seconds to allow adequate time to raise the broom completely, into its uppermost position.
The disclosed method may also include the steps of extending the left blower nozzle, stowing the right nozzle, actuating an air deflector (to channel air into the left blower nozzle), adjusting the height of an air channel (to duct air efficiently across the road surface), and blowing air to the right of the truck. Similarly, the method may include the steps of extending the right blower nozzle, stowing the left nozzle, actuating an air deflector (to channel air into the right blower nozzle), adjusting the height of the air channel, and blowing air to the right of the truck. If necessary, the blower can also be turned off while the nozzles are re-oriented, and then turned on again.